Lighting device



Jan. 2, 1934. w. A. VILLIERS LIGHTING DEVICE Filed June 7, 1952 PatentedJan. 2, 1934 UNITED STATES 1,941,503 LIGHTING DEVICE William AmherstVilliers, Knightsbridge, London, England, assignor to The GeneralElectric Company Limited, London, England Application June 7, 193 inGreat Brita 3 Claims.

This invention relates to lighting devices of the kind in which a sheetof light is thrown to a distance laterally, and more particularly toairport landing lights.

A lighting device of the kind specified, according to the presentinvention, comprises a framework, a plurality of trough reflectors orrows of trough reflectors mounted horizontally on the framework oneabove another to direct the light in the same lateral direction and aplurality of lamps arranged along longitudinal axes of the reflectors.The trough reflectors are preferably of parabolic cross section and thelamps are arranged substantially along their focal lines. The reflectorsor rows of reflectors may each be adapted to rotate about a longitudinalaxis and means may be provided for rotating all the reflectorssimultaneously, whilst further means may be provided for rotating onereflector or row independently of the others. The lamps may be of thetubular incandescent type having their filaments arranged alongthe'longitudinal axes or focal lines of the reflectors. Alternativelythe lamps may consist of luminous electric discharge tubes arrangedalong the longitudinal axes or focal lines of the reflectors.

One construction in accordance with the invention will now be described,by way of example, with reference to the accompanying drawing whichshows a diagrammatic end elevation of a lighting device for illuminatingan airport landing ground.

With reference to the drawing, three horizontal rows 1 of parabolictrough reflectors are mounted on a tubular framework 2. Each rowconsists of three trough shaped glass reflectors, such as 3, ofparabolic cross section arranged end to end in a suitable box 4. Thelamps, which cannot be seen in the drawing, are of the tubular typehaving a long axial incandescent filament. A removable glass cover 5 isarranged in front of each reflector and suitable clamps (not shown) areprovided for clamping the covers in position in a water-tight manner.Suitable baflle plates 6 are provided in front of each lamp to cut offany light which may be thrown upwards. The lamp switches (not shown) arearranged inside the boxes 4 behind the reflectors 3 and are accessiblethrough doors '7.

Each box 4 is mounted on pivots 8 arranged at each end of the box, sothat the box can rotate about a longitudinal axis. A slotted lever 9 isadapted to move a rod 10 in an axial direction, the end of the rodengaging the slot 11 2, Serial No. 615,796, and in June 18, 1931 in thelever 9, whilst the rod 10 is coupled to the respective boxes 4 bymembers 12, which are pivoted to the rod 10 at 13 and clamped to therespective boxes at 14. The clamped end of each member 12 engages acircular slot 19 on the associated box 4 so that by slackening off theclamp 14 the box may be rotated independently of the member 12. Thelever 9 serves to rotate 'the boxes 4 simultaneously so as to tilt theresultant beam of light up or down, whilst for the purposes ofadjustment any one box may be rotated independently of the others.

The framework 2 is mounted on a turntable 15 provided with wheels 16engaging a circular track 1'7, thus enabling the device to be rotatedeasily to any desired position. When in position the turntable may befixed by means of a clamp 18 comprising a butterfly nut coacting with aclamping plate on the turntable l5 and a fixed bolt extending through ahole in the turntable.

Furthermore in an illuminating device in accordance with the invention,since the source of light should be linear, it is obvious that luminouselectric discharge tubes would be very suitable for this purpose. Insuch a case the auxiliary apparatus such as the transformer, in the caseof high voltage cold cathode luminous electric discharge tubes, as wellas the ballast impedance and starting apparatus, where necessary, in thecase of hot cathode luminous electric discharge tubes, could be mountedin the housings behind the trough-shaped reflectors, in the same manneras is described for the switches for the electric incandescent lamps.

Although the example has been described with regard to mirrors parabolicin cross section, it is to be understood that the invention is notrestricted to the use of such mirrors.

I claim:-

1. An airport landing light comprising a framework, a plurality oftrough reflectors pivotally mounted horizontally one above the other inthe framework so as to face in substantially the same direction, aplurality of horizontal pivots extending axially of the reflectors aboutwhich the reflectors are individually rotatable, means for connectingthe reflectors together for rotation in the same direction about theirindividual pivots, and means for disconnecting the individual reflectorsfrcm said connecting means for individual rctative adjustment.

2. An airport landing light comprising a framework, a plurality ofhorizontal trough reflectors pivotally mounted one above the other sothat each can rotate about a separate horizontal axis,

3. An airport landing light comprising a framework, a plurality oftrough reflectors arranged horizontally one above the other and eachpivoted at its ends to the framework, a rod pivotally connected to eachof the reflectors so that they all face in the same lateral direction,means for moving the rod to rotate the reflectors together in the samedirection about their pivots and means for varying the point at which areflector is coupled to the rod whereby the individual reflectors may berotated without moving the rod.

WILLIAM AMHERST VILLIERS.

